The purpose of this study is to examine the nature of the enzymes in rats involved in the catabolism of thiamine. In addition, the effect of chronic exposure of rats to ethanol, carbon disulfide and disulfiram on the state of thiamine nutrition in the exposed animals will be examined. Finally, experiments will be carried out examining the utility of high pressure liquid chromatography in separating and identifying thiamine, its derivatives and its metabolites in animal tissues and urine.